Centrifugal dewatering machine



March 1954 F. R. WASSBERG CENTRIFUGAL DEWATERING MACHINE 2 Sheets-Sheet 1 Filed Dec. 15, 1949 make) W MRN INVENTOR ATTORNEYS.

2 Sheets-Sheet 2 Filed Dec. 15. 1949 ATTORNEYS.

Patented Mar. 2, 1 954 UNITED STATES 0F F HIE.

CENTEIFUGAL DEWATERIN G MACHINE Frank R Wassberg, Coleraine, Minm. Application December 15, 1949; SerialNo. 133,019"

1 Clainn (01. 210.4 2)

Thisinvention relates to ameans forexpelling excess. or free moisture from. moisture samples taken from washed iron ores.

The method of securing dependablemoistu-re samples from iron ore shipmentshas been-a seriou-s problem and two general methods have been conventionally employed for many years, theseheing the moisture box and the car drainage methods. The moisture box is soconstructed that a sample placed therein must be allowed to drain for approximately 24' hours. Thed'ifiiculty arising from use of this method resides in the length of time required to calculate themoisture for gradingpurposes, and the possibility of contamination.

' In the car drainage method railroad cars are allowed to drain a specified time, based on comparative tests made over a period of years. By this method the calculated moisture is obtained quickly with satisfactory results, However, dif-- I ficulties are experienced Whenthe time is shortened by the railroad company switching out the loaded cars before drainage is complete. Difliculties are further experienced when the ore is subjectedito weather conditions during thedrainage period.

It is an imp-ortantobject of the present invention. to provide a. means for, taking moisture samples that will expel the. water contained in said samples in excess, in minimum time.

Another'important object is. to provide ameans of the type stated which will. de-water the: samples in such, a manner as to permit the moisture; content to becalculated with greataccuracy.

An, important object is to permit the calculationof the moisture content as soon as possible.

Another important. object is to. provide a machine of the type stated which will make it possible to make dependable moisture determinations on structure drill cuttings,- which are invaluable in estimating the grades of unmined ore.

With the foregoing and other objects in View which will appear as the description proceeds, the invention consists of certain novel details of construction and combinations of parts, hereinafter more fully described and pointed out in. theclaim, it being understood, that changes may be-made in the construction and arrangement of parts without. departing from the spirit of the invention as claimed.

- Referring to the drawings Fig.1 is afront, elevationaloviewzota centrifuge; up

2 de-watering machine constructed in accordance with theinvention.

Fig; 2- is-a-side elevational view.

Fig. 3 is an enlarged vertical section throug the-upper end of the machine.

Fig. 4 is a section taken substantially on line i -4 Qf-Fig. 3.

Referring to the drawings in: detail, an; electric motor 5 -is controlled by time switchG so that an attendant, after turning on the motor-canproceed to other work withoutthenecessity of paying attention to the machineduring; its op eration. Themotor 5 is mounted upon a'bracket l suppo-rted bya cross bar-8 securedas at 9-to-up-- w'ardly'converging legs lil'and H of a supporting frame that also includes the rear leg l2; the'legs Ill," It, and i2 converging upwardlyand being secured at their upper ends to a vertically extend ing support I3 which can be formed from" channel material, the lower end of said verticalsupport l-3' being supported upon a horizontally extending support [4 which-can also-be a channel member, the endsof thehorizontal support [4' being supported by feet I 5 which can-beboltedor otherwise secured to asupporting surface S. Ex tending rearwardly from the medial portion of the horizontal support M is the rearwardlyex= tending horizontal supporting member f6 se'- cured against-movement by means of 'bolts H extending into the supporting surface-S, therear' end of the member [6 being secured to-andgsup= ported in elevated position by afoot l8;

Secured-- toand extended forwardly from the medial portion of the vertical support i3 is the ,lower bearing bracket l9.

Thus collar 20" disposed above bushing 21 onthe centrifugeshai't 22-=journaled in the bearing, is disposediimmediately above said lowerbearing bracket It, as best. seen from Figs; 1 and 2. Below the lower hearing, a flexible flanged-couplingzt connects the lower end of the centrifuge shaft 22 to the motor shaft 24- of'the electric motor 5'.

Extended forwardly from the upper portion of thevertical support Iii-is the upper bearing" 25,- and that'portion: of thecentrifuge shaft 2-2--ex-- tending through said upper bearing is provided with the bushing 26.

Referring now to Fig. 3, theupper ends? thecentrifuge shaft 22 is extendable intoa sleeve z'f having at its lower end the diametrically-om posed slots 28 receiving cross pinkdthat'extends' through the centrifuge shaft 22. Thus, the sleeve" Zlcan be dropped upon the upper end of the shaft 22 and-isthus-keyed thereto for rotation with and by the-shaft.

Rigid with the lower end of the sleeve 21, and extending upwardly therefrom, is the base portion 30 of inverted frusto-conical formation, this base portion increasing in diameter to its point of intersection with the upper portion 3| of the sample-receiving container or receptacle, the upper portion 3| or hood, being of frusto-conical formation and increasing downwardly in diameter to its point of intersection with the base portion 30 of said receptacle. At the point of intersection the receptacle is of course of greatest diameter, and at this point is provided with a circumferential series of openings 32 through which excess moisture can be expelled on operation of the centrifugal de-watering machine.

Water expelled through the openings 32 is driven into a cylindrical shield 34 the bottom of which is closed by frusto-conical skirt 35, so that said water must of necessity fall into an annular trough-like bottom provided in the shield, so as to drain through opening 36 in which is fitted one end of a drain hose 3'1. The receptacle for receiving the moisture sample extends through the opening 38 provided in the upper end of the frusto-conical bottom 35 of the shield. The frusto-conical skirt 35 is secured at its lower edge to the lower edge of the cylindrical shield 34, and extends upwardly to a location spaced substantially below the point of greatest diameter of the receptacle, intersecting with the base portion 30 of said receptacle intermediate opposite ends of the base portion, the skirt 35 being inclined oppositely to the base portion. The construction permits th base portion to be completely removable, while at the same time the receptacle and the shield are automatically centered and the entire structure held in exact alignment during operation, which is desirable to insure complete accuracy in operation for even distribution of water flowing through the several openings 32 and uniform release of said water into the shield so that proper drainage is assured through the drainage tube 31. In this connection, the frustoconical skirt 35 intersects as before mentioned with the cylindrical shield at the bottom end,

with the tube 31 opening from the bottom of the shield. The skirt 35 and shield 34 thus define an annular trough which at its lower end is of acuteangled cross-sectional configuration, with the drainage being at the bottom of the angle, thereby to insure complete drainage of all moisture from the shield.

The shield is rigid with a bracket 39 that is seated upon the upper end of the vertical support l3.

. A will be seen from Fig. 3, the sleeve 21 ex tends upwardly within the lower portion of the base 30 of the receptacle, and accordingly, I provide a disc-like false bottom 33 in said receptacle, said false bottom 33 closing the upper end of the sleeve 21. 7

The operation of the machine will now be readily appreciated. The moisture sample, in an amount determined most practical by experience, is deposited upon the bottom 33 of the receptacle, after having been taken in the standard method from a plurality of car lots and crushed to minus inch mesh. The motor is turned on, and as previously noted, the operation of said motor is timed, so that the attendant need not remain at the machine during the de-watering of the sample.

From the results of many tests, experience shows that 25% of the excess water is expelled in one minute, and after two minutes, approxi- 4 mately 99%. From 2 to 10 minutes, very little change is noticeable and most of the wash ores tested showed that after 4 minutes practically all the excess water is driven out. A period of 7 has been adopted as standard for de-watering ores, in most instances.

After the water has been expelled, a selected portion of the sample is placed in a drying oven and dried at 212 Fahrenheit for 3 hours. The moisture percentage is then calculated.

The grading of iron ore becomes more complicated each year, because the various elements are now graded more closely to the guarantee than in former years, and it is very important that the iron natural content be calculated as soon as possible. It is important to secure proper moisture results, as experience has shown that difierent areas in one mine will vary materially in moisture.

It has been found that a machine constructed as illustrated and described herein is admirably suited for the purposes indicated, and it is now possible, where it has not previously been possible, to make dependable moisture determinations on structure drill printings, which are invaluable in estimating the grades of unmined ore.

In operation, it will be seen that the whirling of the centrifuge receptacle at high speed will cause the excess water to travel downwardly along the wall of the upper portion 3! of the receptacle, while water driven out of that part of the sample disposed within the lower portion 30 travels upwardly along the wall of said portion 30. All the water, whether travelling upwardly or downwardly, is eventually expelled through the single circumferential series of openings 32 and drained oif.

Upon termination of machine operation, the centrifuge receptacle is simply lifted out of its seat 38 and off the end of the shaft 22, for further processing of the moisture sample. Other moisture samples are then deposited in the receptacle, and the receptacle returned to the position shown in Fig. 3, in which position it is ready for further ole-watering of samples.

What is claimed is:

In a centrifugal ore dryer an elongated shaft mounted to rotate about a vertical axis, a prime mover, a flexible flanged connection between said prime mover and said shaft adjacent the lower end thereof for rapidly rotating said shaft, said shaft having a cross pin extending therethrough adjacent its upper end, an elongated sleeve removably mounted on the shaft in an encircling relation with the upper end thereof, said sleeve having diametrically opposed recesses opening through its lower end for receiving the cross pin and supporting the sleeve on the shaft for rotation therewith, an inverted frusto conical container carried by the sleeve for rotation therewith above the shaft, a frusto conical hood carried by the container and extending inwardly above said container, said hood cooperating with the container in confining ore to be dried, and the junction of said container and said hood having an annular series of peripherally spaced openings extending therethrough through which is dis-'- charged water removed by centrifugal force from ore in the container, an elongated shield surrounding the container and the hood in concentric spaced relation thereto, a frusto conical wall carried by the shield and extending inwardly and upwardly from the lower end of the shield to a plane intermediate the upper and lower ends of the container to define with the shield an annular Number utter in which is collected Water which is dis- 2, 5 6 charged through the peripherally spaced openings. 2, 7 4

FRANK R. WASSBERG.

References Cited in the file of this patent z l l z go UNITED STATES PATENTS 524,499 Number Name Date 1,105,954 Beach Aug. 4, 1914 10 1,279,287 Davies Sept. 17, 1918 1,770,383 Altorfer July 15, 1930 1,963,476 Smith June 19, 1934 Name Date Schmelzer Sept. 1, 1936 Dunham Mar. 10, 1942 FOREIGN PATENTS Country Date Great Britain Feb. 14, 1924 France May 13, 1921 OTHER REFERENCES Mechanical Engineers Handbook by Lionel Marks, 4th edition, pages 935-940. 

